Reflecting electric lamp



June 28, 1932. DOUGLAS 1,864,642

REFLECTING ELECTRIC LAMP Filed Feb. 5, 1950 2 Sheets-Sheet 1 d mafia?" fizzy J7. @au g Zas June 28, 1932. H. A. DOUGLAS REFLECTING ELECTRIC LAMP Filed Feb. 3, 1950 2 Sheets-Sheet 2 Patented June 28, 1932 UN [TE STATES HARRY ATDOUGLAS, 'OF BRQNSoN, MICHIGAN nnrLEc'rme ELECTRIC LAMP Application filed February 3, 1930. Serial no. 425,546.

My invention relates to incandescent electric lamps and their mountings and is of particular service where such mountings are in p the form of concave reflectors. My invention includes the provision of spring means Which maintains a lamp base receiving socket in assembly with the lamp mounting through the intermediation of the lamp base. That is the spring meanspresses upon the lamp base, the lamp base presses upon the socket that receives it, and the lamp socket ispressed against the mounting by the lamp base. My invention is of particular service in connection with parabolic reflectors and when the invention is thus applied the construction and arrangement of the parts are such that the lighting center of the lamp filament and the focus of the reflector are made coincident. In this embodiment of' the invention the lamp socket is provided with three points of contact with the back of the reflector distributed around the socket axis. These three 'pointsof contact are in a plane that is'perpen'dicular to the socket axis to bring this axis into coincidence with the reflector axis which is surroundedby the socket. This result is assured by providing an opening through the crown of the reflector which has portions margining this opening that prevent canting of the socket serving, in conjunction with the aforesaid three points of contact, to maintain the reflector and socket axes coin cident. The base of the lamp is snugly received Within the bore of the socket to bring the lamp axis into coincidence with the socket axis, so that the lighting center of the lamp filament, which is on the lamp axis, is'on the common axis of the socket and reflector. The spacing between the lighting center of the incandescent lamp filament and the place where the lamp socket is pressed against the reflector is substantially equal to the spacing between the focus of the reflector and the portion of the reflector at which the pressure 45 from the lamp socket is received.

The invention will be more fully explained in connection with the accompanying drawings in which Fig. 1 is a longitudinal side view of an incandescent lamp in association with contiguous parts some of which are shown in section-and some in elevation; Fig. 21s a sectional view on line Qr-2 of Fig. 1;

F ig. 3illustratessome of the parts'as they appear in Fig. 1 with the socket in elevation and a spring carrier partially in elevation and partially in section; Fig. 4 is a view showing parts that appear in Fig. 3 and taken at rightangles to the direction in which Fig. 3 is taken, parts being shown in section and hro-' ken away; Fig. 5 is a View, generally similar to Fig.,3,.taken in a direction-at right angles to the direction in which Fig. 3 is taken and showing portions in addition; Fig. '6 is a sectional'view of a complete automobile head lamp containing the preferred structure of 55 my invention; Fig. 7 is a sectional View on line 7- 7 of Fig. 3; and Fig. 8 is a perspective view showing variousparts of the structure in separated relation.

The head lamp illustrated is inclusive of a parabolic reflector 1 whose parabolic reflect ing-face is covered by alighttransmitting closure-2,'-which may beof glass. This closure is held againstthe front ofthe reflector by an assembling ring 8 which also serves to assemblethe reflector With a concave lamp back ly The construction of the peripheral rim ortion of the reflector enabling the assemb yof the refiector'with the lamp back and theflconstruction of the parts Band 4 may 30 be of any well known or suitable character and form'nonovel parts in my present invention on which account further description of these parts need not begiven. The embodi ment of the invention illustrated is inclusive $5 of an incandescent lamp having a generally cylindrical base 5 which is laterally ex tended, as bymeans of two diametrically opposite bayonetpins or projections 6. The generallycylindrical socket 8 has a bore'in which the. lamp base 5 is snugly received, whereby the lamp 'aXis and the socket axis are made coincident. The socket is of metal and is longitudinally split, so that its bore may be made slightly less in diameter than 96 the diameter of the lamp base, whereby the intimacy of en-agement between the. lamp base and'its'soc'et is further assured. The lamp socket has bayonet channels which afford seat-s9 and 10 for the bayonet pins or we projections 6. The marginal portions 7 of the opening in the crown of the reflector are equidistant from the reflector axis and snugly engage the cylindrical lamp socket 8, whereby the axis of the lamp socket may be brought into coincidence with the axis of the reflector. The lamp socket is provided with three points 11, 12 and 13 for contact with the back of the reflector. These points of contact'are distributed around the socket axis and are in a plane that is perpendicular to the socket axis to bring this axis into coincidence with the reflector axis; The lighting center of the bright light producing lamp filament 14 is upon the lamp axis when all of the parts are properly assembled. The spacing between this lighting center and the three points of contact 11, 12 and 13 is equal to the spacing between the focus of the reflector and the places upon the reflector where the contact points 11, 12 and 13 are engaged. The lighting center of the lamp filament is thus accurately brought into coincidence with the focus of the reflector without the necessity of further adjustment.

Some suitable spring means is employed for pressing upon the lamp base to bring this base, where laterally enlarged as at 6, into engagement with the lamp socket and to bring the parts 11, 12 and 13 upon the lamp socket into engagement with the reflector,

whereby the coincidence of the lighting center of the lamp filament and focus of the reflector is eflected. Such spring means is illustrated as being inclusive of two forwardly spring pressed circuit terminal contacts 15 and 16 which are engaged with the contacts 17 and 18 upon the rear of the lamp base, the latter two contacts constituting the terminals of the bright light producing filament 14. A dim light producing filament 19 is included between the contact 17 and a metallic sheath which surrounds and constitutes a part of the lamp base 5. By suitable switching mechanism, not illustrated, either the filaments 14 and 19 may be included in cir? cuit or both may be excluded from circuit.

26 which are contracted toward each other until they clear the opening enlargements 25, whereupon they spring outwardly to engage the front of the reflector. The reflector at the opening enlargements 25 is snugly received between the lugs 26 and the body of the carrier 23.

Changes may be made without departing from the invention.

Having thus described my invention, I claim a 1. The combination with a mounting having an opening therethrough, of a socket in said opening receiving the base of an incandescent lamp, said base having bayonet pin and bayonet channel engagement with said socket, and said socket being provided with three or more contact points spaced apart around the axis of the socket for positioning the socket with respect to the mounting, a springpressing the lamp base against the socket and through the intermediation of the lamp base pressing the socket against the mounting at said contact points, and a carrier carried by the mounting and carrying said spring, said carrier surrounding the socket and having three or-more points of anchorage upon the mounting, said points being spaced apart around the axis of the socket.

2. The structure of claim 1 wherein the carrier is provided With spring fingers which are received within lateral enlargements of the opening that is formed through the mounting, said fingers having lugs thereon that are engageable with portions upon the mounting that margin the opening.

3. The structure of claim 1 wherein the socket and carrier are split longitudinally.

In witness whereof I hereunto subscribe 1 my name.

HARRY A. DOUGLAS.

The contacts 15 and 16 are slidably mounted within cylindricalmetallic bearings 20 and 21 which are carried by and pass through a contact carrying disc of insulation 22. This disc of insulation is, in turn, provided upon a generally cylindrical metallic carrier 23. The element 23 is carried by the reflector. In the preferred embodiment of the invention the carrier 23 is provided with spring fingers 24 which are received within lateral enlargements 25 of the opening that is formed through the crown of the reflector.

v These fingers are formed with lugs 26 that are engageable with portions upon the reflector that margin the opening enlargements 25. The carrier 23 is desirably longitudinally split throughout, so that it may be contracted to permit of the passage of the lugs 

